But the system was only in its second year of reporting and was showing improvements, Parata told Radio New Zealand today.

"Our consistent message has been that this information is part of an overall discussion with teachers and it does not displace or replace parents talking to their child's teacher about what's happening for them," she said.

"National standards will get better and better, as did NCEA [National Certificate of Educational Achievement]."

Parata said it was a new way of understanding how children were progressing and a "journey of continuous improvement".

The research had prompted workshops with teachers to improve reporting to parents, Parata told RNZ.

Moderation would also improve to prevent cases where pupils previously not meeting standards jumped to the standard the following year, she said.

Almost 10 per cent of school reports in the study's sample made no mention of the national standards.

However, the study showed schools were increasingly reporting national standards information to parents from 2010 to 2012, and more end-of-year reports referred to the national standards, reaching 91 per cent last year.

The proportion of reports that sufficiently described pupil achievement in relation to the national standards also increased.